1. Department of Neurosurgery, Shengjing Hospital, China Medical University, Shenyang, China
2. Department of Neurosurgery, the Seventh Clinical College of China Medical University, Fushun, China
3. Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, China
4. Department of Hepatobiliary and Pancreatic Surgery, Fuyang People's Hospital, Anhui Medical University, Fuyang, China